It normally has a big sign outside that tell you how much the drinks are, so is up to you if you go in. If you cannot afford to pay 40-60baht for a beer, why would bother being there on holiday.

I know its different for people who live there and are on limited funds, but even at 40-60 baht that is pretty good value in my eyes.
In your search for cheap beer, bear in mind the guys whose business it is. He has to make a profit somehow to pay his rent, his staff, overheads etc, and I can assure you that you are not going to get rich at selling beer at 40-60 baht every hour of the day, with people sitting there for 2 or 3 hours and just drinking 2 or 3 beers